Draft regulator for orchard heaters



Junesw,`1944. yW, C, scHEU $2,350,830

DRAFT REGULATOR Fon ORCHARD xmms Filed Nov. 1. 1940 Y 2 snee'psshet 1 @wa/Moa PV/41. IAM C'. Scl/su,

June 6, 1944. w. c. scHEu DRAFT REGULATOR FOR ORCHARD HEATERS 2 Sheets-Sheet 2 Filed Nov. 1,I 1940 Patented June 6, 1944 EATE William C. Scheu, Upland, Calif.; Henrietta Scheu, W. Leland Scheu, and C. H. Dekker, executors of said William C. Scheu, deceased, assignors to Scheu Products Company, Ltd., a corporation of California Application November 1, 1940, Serial No. 363,877

Claims.

' particularly suited to automatic, heat-responsive regulators used with vaporizing type, liquid fuel orchard heaters; but the invention is not necessarily limited thereto since it may be employed on heaters using other types' of fuel and in connection with manually operated draft regulators as Well as with automatic regulators. In heaters of the liquid fuel vaporizing type, a vaporizing flame is maintained at ornear the surface of the fuel contained in the heater in order to cause vaporization from the surface of the fuel. The fuel vapors pass upwardly, along with some air, into a stack where additional air is mixed with them to cause substantially complete combustion of the vapors in a main flame at a point removed from the vaporizing flame. A heater of this general type provided with a stack forming the main combustion chamber is shown in my U. S. Patent No. 1,930,863, issued October 17,v 1933.

Orchard heaters. are usually provided with one or more relatively large air admitting openings in the body to admit air to the vaporizing flame, not only tc keep that flame burning but also to help maintain the main ame. With such an arrangementJ it s preferable to supply a relatively large quantity of air to the vaporizing chamber for the vaporizing flames when the heater is rst ignited and until the vaporizing chamber has become heated. After the Vaporizing chamber is well heated and the main combustion flame well established, a smaller amount of heat from the vaporizing flame is required to vaporize the fuel; and if the air supply is not reduced to diminish the flame,` there will be a tendency to vaporize an excessive amount of fuel. These relations all depend on the heat generated in the vaporizing chamber and are substantially independent of the temperatures existing where the main combustion takes place in the stack.

In order to obtain proper and satisfactory operation of an orchard heater of this character during the period of normal burning, it is necessary to restrict the flow of air into the Vaporizing chamber after the period of initial heating. Restriction `of the air flow may be done manually or by automatic heat-responsive means. In either case, itis desirable to provide draft regulating means adequate to obtain the properow of air required to maintain the desired rate of combustionin the heater. This is particularly important when the heater is operating with a minimum flame.

When making draft regulating devices for orchard heaters it is highly desirable from a manufacturing standpoint to standardize on one construction which isV as simple as possible. At the same time, these regulating devices may be applied to many different kinds and styles of heaters burning different fuels. Under these widely Varying conditions which are encountered in actual operation, diiferentamounts of air are required to maintain a given rate of combustion in the heater, that is togenerate a given amount of heat. However, this condition is not Vcritical except when it is desired to maintain the lowest possible ame in a heater, since if the air admitted is in excess of the minimum required, fuel is wasted, and if the air admitted is less than the minimum required, the fire dies out.

It has been found that the best results are obtained from a regulator which can be adjusted to admit the minimum amount of air proper for the conditions under which each heater operates. In this way the proper minimum air opening can be adjustedI by the operator for his particular heater, and the regulation is not left to unskilled-labor ordinarily .not competent to properly adjust the heaters. In this way loss either from fuel wastage or inadequate heating is avoided.

It is therefore the principal object of my invention to provide a draft regulating device for orchard heaters which is operable to provide a comparatively unrestricted flow of air into the vaporizing chamber during the preliminary ignition period, and subsequently to restrict admission of air to the vaporizing chamberA during the Vburning period, but .which can originally be set to admit air to the vaporizing chamber during the burning period at not less than a predetermined minimum rate.v i It is also an object of my invention to provide in a regulator of the above type, means for adjusting the minimum amount of air admitted to suit any conditions encountered, and for maintaining the adjustment constant after once determined.

Another lobject of my invention is to provide in a regulator of the above type means for establishing a constant minimum flow of air past the regulator, independently of means for adjusting the regulator to admit air at varying greater rates.

Another object is to provide a simplified heatresponsive draft regulator which may be standardized for manufacturing purposes and which at the same. time provides the necessary flexibility of operation to permitl its use with many different kinds of heaters and fuels.

Another object Yof my invention is to provide,

in combination with a pivotally mounted draftregulating plate and heat-responsive means for releasing the plate to effect air restriction, means with apertures in the plate and subsequently by positioning the plate.

These objects of my invention have been attained by providing, for an orchard heater having an air-admitting opening, a draft regulating device which comprises a draft regulating cap which is mounted on the heater and provided with aperture-means admitting air to the opening inthe heater-and adjustable closure means mounted on.,Y the Vcap and Vassociated with the aperture means thereinto vary the open areas of separate portions of the aperture means to admit to thevheater during the burning operation a selected minimum amount of air or a selected larger amount. Ina preferred form of my invention the draft regulatingV cap comprises an annular body with an air-admitting opening and a draft regulating plate pivotallyjmounted adjacent. the opening; but in asimplied form the body and platemay be made integrally. Y

Howzthe above objects and advantages of my invention, as Wellas others not specifically mentioned, are obtained will be more readily apparent from thefollowing description and theV annexed drawings, in which: Y t i Fig. 1 is a fragmentary plan view of a typical orchardY heater,V showing a draft-regulator constructed Yin accord with my invention applied thereto;` ,A 7 v Fig. `2'V is an enlarged vertical section on line 2-2 of Fig. `1, showing alternate positions of the weather cap and the whole regulator in dot-dash lines; Fig. .3l is a plan View of the regulator with the weather cap open and the draft-regulating plate in full air-restricting position; v

Fig. 4'is a fragmentary 'vertical section on line 4--4`oi` Fig.l 1 withthe regulating plate in position to Yimpose comparatively no restriction on air admission;

Figs. 5 and`6 are inverted plan views of the thermostatic means for controlling operation of the'plate; Fig. 5 showing the positionof the thermostatic element when cold and Fig. 6 showing the position of the element when heated;

Figs. 'Tand 8 are fragmentarysecti'ons taken along therim' of the draft regulating plate as indicatedby line 'I--l in Fig. 3 ;`and

t Fig. 9 is a planview, similar to Fig. 3, of a simpliiied form of my invention. Y

There is generally indicated at IIIV in Fig; 1 a portion of a common type `ofvaporizing liquid fuel orchard heater.y As shown in Fig. 4, the heatercomprises'a bowl I I which provides a base for supporting the upper structure and also provides a fuel reservoir, the space within bowl I'I and above the fuel body being a fuel vaporizing chamber. 4Bowl II is provided with cover I2 on which there is a anged central opening I3 at which a suitable stack, not shown, is mounted.

Cover I2 is. provided with an air-admitting opening I5 around the margin of which is an upstanding iiange or collar I6 which is attached at its lower edge to cover I2. Collar I6 is preferably circular in shape and has a depressed central portion which forms a mounting means for a draft tube I1 which is preferably provided to facilitate maintenance' of a vaporizing ame above the fuel body. The upper end of the draft tube II is provided with an outwardly extending flange which engages the upper surface of co1- Alar I5 and is supported thereby. The upper end of draft tube I'I is open for the admission of air;

Vto regulate air restriction by rst cooperating and the open upper end of the draft tube determines the net size of air-admitting opening I5 in the heater.

The draft regulator includes a draft regulating cap, indicated generally at I9, which comprises an annular cap-like body 20 and a draft regulating plate 24 movably mounted on the body which fits snugly down around collar I 8. The central portion of body 28 is cut away to provide an air-admitting opening 2| which is above and approximately the same size as the open upper end of draft tube I1. In this way air going through opening 2I in the regulator body enters the heater through opening I5 in the latter. Draft regulating plate 24 is pivotally mounted at 25 adjacent one edge of air-admitting opening 2I, in which position the plate is movable about pivot 25 to regulate the passage of air through both openings I5v and ZI. Plate 24 is slightly larger in over-all dimensions than opening 2I in order to yengage the upper side of body 2|) when lowered as in Fig. 3.

On the under side of plate 24 is mounted thermostatic control means which comprises a coiled bimetallic strip 28 attached in any suitable manner atv one end to bracket 29, as shown particularly in Figs. 5 and 6. Bracket 28 is attached to plate 24 in any suitable manner, as by bolts or rivets, and vis preferably insulated froindirect engagement with the plate by a layer of heat insulating material 30 between the plate and bracket, as best shown in Fig, 4, in order to retard heat transfer to the bimetallic element. Bimetal element 28 curves through-almost a complete circle when cool, and occupies the position shown in Fig. 5. In this position, it is engaged -by the'end of a holding member in the form of curved arm 32 which is attached to the under side of body 2G. Arm 32 projects downwardly from the body to a position in which the end of thearm engages one side of bimetal strip 28. Engagement of arm 40 with the bimetal element in the manner shown in Figs. 4 and 5 holds draft regulating plate 24 in the rstor raised position, illustrated in Fig. 4. In this rst position, air can pass between plate 24 and regulator body 20 relatively freely and enter the heater through openings 2I and I5. In this first position, sufficient air to maintain the maximum rate of combustion can enter the heater, and therefore air admission may be said to be comparatively unrestricted. It will be noted thatin this first position, plate 24 is biased by gravity towards a lowered position in which the plate restricts the passage of air through opening 2I in a varying degree, according to the amount of movement of plate 24, as will be further described.

Bimetalrelement 23 is enclosed within a rectangular housing 34 attachedy to the under side of plate 24 by bolts or rivets at 35. The inside of housing 34 is preferably lined with heat insulating material 36, such as asbestos, to retard the flow of heat to bimetallic element 28. The hous- ,fing and insulation are slottedat one side to per'- mit arm 32 to pass' through them and into engagement with strip 23;, y v

In response to heat generated within the heater, b-imc'tallic element 23mstraightens somewhat and reaches a position illustrated in Fig 6, which arm 32 no longer engages element-28. As the end of the bmetal elementrslips' past arm 3.2, draft regulating plate 24 is released and per- 'mitted to fall under the force of gravity toa second or air restricting position in which the passage of air to the heater interior is restricted to a greater or lesser degree. IIn the extreme lowered position, the rim of plate 24 engages the flat portion of body-29 around air opening 2 I, and is in the position of maximum restriction.

However, under some circumstances it may be desired that plate 24 not be allowed to reach this extreme lowered position, but that its downward movement be limited to a position in which it restricts the passage of air to a lesser degree and permits the entry of suicient air to maintain normal burning operations at a moderate flame. In order to limit the downward movement of the plate some type of limiting means may be employed; and I prefer in this form of my invention to combine that limiting means with adjustable closure member 40 which is preferably a platellike member movably mounted on the upa per surface of regulating plate 24, as by means of pivot 4l. Y

As may be seen in Fig. 3, the edge of draft regulating plate 24 is notched at 42 for a portion of its length, and the edge of adjusting member 40 is provided with a depending projection 44', shown in Fig. '7, which is slidable along the length of notch 42. AThe upper surface of bodyvZU is provided with an elongated arcuate depression 45 (see Fig. 1) in which projection 44 moves'. The endV of' depression 45 nearer pivot 25'has an inclined surface at 45, When projection 44 is in the main portion of depression 45, plate 24 can drop into engagement with body 29, as shownin Fig. 8. But when adjusting'rniember 40 is Yrotated clockwise as viewed in Fig. 3 until projec-V tion 44 is over the incline 4S as shown in dot-dash .lines at 41, engagement of the projection with thev incline prevents thev regulating plate from cominer into contact with body 20 around its margin; When so held up as shown in dotted'line f 'position 24 of Fig. 4, tlie regulating plate is in its second, or air restricting position, and admits air to opening 2l through the space between the plate and body 20. The amount of air so admitted is regulated by the position along' incline 46 at which projection 44 enga-ges the incline.

Regulating plate 24 is provided with aperture means admitting air to the heater. Typically, this means may be a plurality of air-admitting apertures, as indicated at 48, 49 and 50. These apertures Ymay be holes in the plate completely surrounded by a portion of the plate, but they are preferably notches or indentations in the rim of the plate as shown in Fig. 3. Likewise the aper ture means may be but a single opening, though two or more spaced apertures are preferred. Ac-l cordingly, in the drawings the aperture means is shown y as divided into two spaced aperture means, each of which may comprise but a single aperture or more than one aperture, as shown.

One aperture means is aperture 48. Associated with aperture 48 is adjustable closure member 52 which is rotatably mounted on plate 24 by pivot pin 4l, and is in sliding engagement with the upper surface of the plate to vary the open area `vf`aperturef48- by covering as muclt of aperture 48 as may be' desired. lo'sure mami ber 52 is slotted atli3v and'screw passes through this not. screw 54 operates lock means which, wiieniooseneapemits member 52 to be moved into any desired position tocover a selected por=` tion of aperture 48, and when tightened locks th adjusting member in the selected position. Fig.' 3 shows adjusting member 52 locked in posi tion to cover approximately one-half of aper-A ture48. I 'K l.

- Aperturs a9 and 5U constitute a second spera ture means; and associated with them is adjust'- able closure member 49, so located that when the closure member is moved counterclockwise to the extreme position 40' shown by the dotted linesA in Fig. 3, both these apertures are covered by the solidl plate-like portion of the adjusting member, thus preventing passage ofiair through apertures 4S and 50. Such counterclockwise' movement of closure member 40 is limited by engagement of projection 44 with stop means coniprising the forward end of notch 42 as shown in- Fig. 8 and at 44' in Fig; 3. lAs previously eX- plained, when adjusting member -40 is in thisV position, plate 24 can be lowered to engage bodyl 20 around the rim of the plate. Since apertures 4? andY 50 are closed by member 40, the only airwhich can enter the air admitting opening 2| is that air which enters through the uncovered area of aperture 48.

rClosure members 40 and 52 are provided with upturned tabs 40a and 52a respectively by whichY the members may be grasped to move them. Also, spring 5G is placed o n pin 4l to press -the members against plate 24 to afoi'd frictional resistance to accidental displacement.

With all of one aperture means (apertures 43 and 5G) closed by the member 40, and a portion of the other aperture means (aperture 48) closed by the member 42 as shown in- Fig. 3, the minimum amount of air which can enter thel heater during burning is determined by the size of the open area of aperture 48. The size of thisv open area can be varied as desired by movement of the closure means and when the closure memsber is in its selected position it can be locked there by screw 54. This minimum area is set to maintain the minimum Iiame in the heater under any given set of conditions..

j when a higher same in the heater is desired. and it 1s necessary to admit more air than the.

minimum nas determined in thisv way, closure member 40 is rotated clockwise from the 'dotted une position of Fig. 3, thusprogressiveiy incre-as; ing' the open area of the aperture means formed by aperture 49 and aperture 50. In this way, the open area of the second aperture means is varied is admit additional air above the minimum amount order to maintain a higher rate of combustion during the b-urningoperation, 'and' the range ci adjustment in this manner depends upon the total area of the aperture or aperturesy which can b'e uncovered by movementof closure member 40.

The felation of the parts is such that after aperture 58 has been fully uncovered, projec= tion 44 on the' closure member comes into ensagement with incline 4s on body 2o, with the result that additional movement of member 4l) in the' same direction causes engagement of the projection with the incline at some selected` point along the length of the incline.- As' mentioned previously, this engagement limits the downward pivotal movement of draft regulating plate 24 to stop the plate in a second or air restricting posi-l tion, at somepoint i (see 24V in Fig. 4) 'short of engagement with body 20 around the margi'nof the` plate. Thus there is left a gap' between 4the plate and the, body through ywhich air also may enter opening 2l in order tomaintain combustion at a still.` higher rate. Bythis lastv adjustment, theburningf rate may be raised as farI as desired upto the maximum for that heater. Y

The regulatorV is provided Awith weather cap 6B which is designed to cover draft regulating cap Illas shown in full lines in Fig. 2. The weather cap fits snugly'down around body 20in order toexclude dustor rain from the regulator and from the heater. Weather cap` El! is mounted on the body of the draft regulating cap by means of'a hinge located at one side of body 20. The hingecomprises a bent strap 5I which is attachedl at=A one end tothe side of body in some suitablev manner, preferably by welding. The outeriend of theV horizontally extending portion of strap 6| is formed with a loop to receive one side of rectangular hinge link 52, the ,other side of the linkA beingreceived in aV loop of a second strap 63 which is suitably attached to the weather cap,preferably by'welding'.

Asmay beiseen in Fig. 3, the loop portion of hinge strap 6| which receives link 62 is provided with a pair of stop shoulders 64 against which the two upwardly extending sides of link 62 strike when the weather cap is pivoted about the'hinge to thel open position shown in dot-dash lines at the right hand side of Fig. 2. Engagement of the hinge link with shoulders 64 stops the swinging motion of the weather capshort of engagement with cover I2 ofthe heater, as shown. It is preferred that the weather cap notvbe permitted to come in contact with the heater cover since if it does, the point of engagement forms a fulcrum about which the entire regulator may swing, and an accidental blow against the upper rim of the weather cap tends to dislodge body 20 from its position around body l 6. This is avoided by the hinge construction shown since in the eX- treme open position of the weather cap, it does not contact the heater cover.

The entire regulator assembly, comprising the draft regulating cap and the weather cap, is at-v tached to the heater cover by a `secondv similar hinge. The second hinge is attached to body 2i) at a point preferably diametricallyopposite,A or nearly so, tothe point of attachment of the first hingejust described. This second hinge comprises "strap` 65 attached at one end vto body 20 and provided witha loop at the other end to receive hinge link 6B, the opposite side of the link being receivedin al second strap 61 which is attached to cover I2 of the heater. regulator may thus be' lifted from collar I5 and swing to the left about the second hinge to the position shown by the dot-dash lines at the left The .entire hand side of Fig. 2. In this waycollar I6 is'exn posed to permit refueling the heater and inspection or replacement of draft tube l1. This construction has the advantage that a continuation ofthe motion which places the regulator over collar. I6 on the heater, operates to remove the weather cap from the draft regulating cap, thus leaving the weather cap in the open position las illustrated at the right hand side of Fig. 2. In this position the draft regulating cap is uncovered in order to admit air to the heater and also so that draftregulating plate 24 may be swung back to the position shown in Fig..1A to allow the insertion of the tip of'a lighting torch through opening 2|.

Although I have described a preferred form of my invention which includes thermostatic means for releasing a gravity biased regulating plate, thus permitting the plate to drop to an air restricting position at which air is admitted at a predetermined rate to maintain combustion at a desired rate, it is to be understood that my invention is not limited to the inclusion in the regulatorrof such thermostatic means. Bimetallic element 28, its housing, and holding member 32 may be omitted and the draft plate manually swung from an open position during the original ignition period to its air restricting position which is maintained during normal burning. This change doesA not, however, effecttheoperation of the adjustable closure members 40 and 52 or the function and operation of projection 44 in varying the area of the openings through which air is admitted to the heater.

A still further simplification of my invention maybe made if desired, by making the draft regulating plate Xed instead of pivoted. In this event, the draft regulating plate and the body of lthe draft regulating cap may be made integrally in one piece and I show a regulator'of this construction in Fig. 9. In the simplified embodiment of my invention, draft regulating cap 19a is shaped the same as body 20 of the form previously described with the top surface of the body not cut away but having a plate portion 24e which operates as the draft regulating plate. This plate portion of the draft regulating cap is provided with two spaced'aperture means at 1U and .1| with which are associated respectively adjustableclosure members 52e and 40e. 'Ihese closure members operate to vary the open area of the associated aperture means inthe same manner as previously described. The draft regulating cap is provided with a weather cap 60, and the entire regulator is mounted on the heater in the same manner as previously described.

Having described various embodiments of my invention, it isto be understood that there may be made various changes in the shape, location and arrangement of the several parts of my improved regulator without departing from the spirit and scope of my invention; and consequently it is to be understood that the foregoing description is to be construed as illustrative of rather than rlimitative upon the appended claims.

I claim:

1. In an orchard heater draft regulator, in combination with a cap provided with air-admitting aperture means, a device for regulating admission of air through said aperture means comprising: a iirst adjustable closure member movably mounted on the cap and movable to selected positions over a portion of the aperture means to vary the open area of the aperture means in said portion; means holding the first closure member in a selected position; and a second adjustable closure member movably mounted on the cap and movable over another portion of the aperture means to varyV the open area of the aperture means in said other portion.

2. In an orchard heater draft regulator, in combination with a cap provided with air-admitting aperture means, a device for regulating admission of air through said aperture means, as set forth in claim l., and comprising in addition stopmeans associated with the second closure member to prevent movement' of the second closure member over the rst mentioned portion of the aperture means.

3. In an orchard heater draft regulator, in combination with a cap provided with two spaced airadmitting aperture means, a device for regulating admission of air through said aperture means comprising: a first adjustable closure member movably mounted on the cap and movable to selected positions over one of said aperture means to vary the open area of that aperture means; means holding the rst closure member in a selected position; and a second adjustable closure member movably mounted on a cap and movable over the other of said aperture means to vary the open area of the other aperture means.

4. In an orchard heater draft regulator, in combination with a body member provided with an air-admitting opening, a device for regulating admission of air through said opening comprising: a draft regulating plate pivotally mounted on the body member adjacent said opening and movable to restrict in varying degrees passage of air through said opening, the plate providing airadrnittlng aperture means communicating with said opening; and an adjustable closure member movably mounted on the plate in sliding engagement therewith and having a depending projection, movement of the closure member in one direction progressively uncovering the aperture means to admit more air therethrough and additional movement of the closure member in the .same direction bringing the projection into engagement with the body member and limiting pivotal movement of the regulating plate toward a position of maximum air restriction to limit the restriction imposed by the plate on air passing through the air-admitting opening.

5. In an orchard heater draft regulator, in combination with a body member provided with an air-admitting opening, a device for regulating vadmission of air through said opening comprising:

a draft regulating plate pivotally mounted on the body member adjacent said opening and movable to restrict in varying degrees passage of air through said opening, the plate providing two spaced air-admitting aperture means communieating with said opening; a first adjustable closure member movably mounted on the plate and adjustable to selected positions to vary the open area of one of said aperture means; lock means holding the first closure member in a selected position; and a second adjustable closure member movablyv mounted on the plate, movement of the second adjusting member in one direction progressively uncovering the other aperture means to admit more air therethrough and additional movement of the second member in the same direction limiting pivotal movement of the regulating plate toward a position of maximum air restriction to limit the restriction imposed by the plate on air WILLIAM C. SCHEU. 

